This invention is directed to new chemical compounds, especially useful as antagonists of the slow reacting substance of analphylaxis (SRS-A) and the major components thereof, the leukotrienes C.sub.4, D.sub.4 and E.sub.4 ; as well as of leukotriene B.sub.4.
It is known that certain substances play an important role in inducing an allergic reaction, such as asthma, allergic bronchitis or allergic rhinitis, in man. Examples of such substances are SRS-A and its major components, the leukotrienes. See: P. Borgeat and P. Sirois, J. Med. Chem., 24, 121 (1982) and P. J. Piper, Ann. Rpts. Med. Chem., 15 69 (1980).
SRS-A and the leukotrienes C.sub.4, D.sub.4 and E.sub.4, affect the smaller peripheral airways of the larger central passages such as the trachea and the bronchi. In the presence of an allergic trigger like pollen or dust, these leukotrienes are manufactured from fatty substances trapped in the membrane of a triggered cell. A series of reactions within the cell generates this mixture of leukotrienes which may then pass through the cell membrane into the bloodstream. Once in the blood, these leukotrienes constrict air passages producing breathlessness.
Leukotriene B.sub.4, which is not part of SRS-A, is an important chemotactic factor which induces migration of polymorphic cells and thus contributes to both inflammation and allergic diseases.